A nanofibrous catalyst for in the electrolyzer and methods of making the catalyst. The catalysts are composed of highly porous transition metal carbonitrides, metal oxides or perovskites derived from the metal-organic frameworks and integrated into a 3D porous nano-network electrode architecture. The catalysts are low-cost, highly active toward OER, with excellent conductivity yet resistant to the oxidation under high potential operable under both acidic and alkaline environments.

A water treatment system with a photocatalytic nanocomposite sheet, an adsorbent layer, and a fibrous filter, wherein the photocatalytic nanocomposite sheet comprises polymethylmethacrylate and silver phosphate, the adsorbent layer comprises plasma activated carbon nanotubes, and the fibrous filter is a composite of polymethylmethacrylate, polyvinylidene fluoride, and polyvinylpyrrolidone polymer fibers, with carbon nanotubes that are dispersed within the polymer fibers and silver nanoparticles that are deposited on the polymer fibers. Various embodiments of the water treatment system and methods of fabricating the photocatalytic nanocomposite sheet, the adsorbent layer, and the fibrous filter are also provided.

A water treatment system with a photocatalytic nanocomposite sheet, an adsorbent layer, and a fibrous filter, wherein the photocatalytic nanocomposite sheet comprises polymethylmethacrylate and silver phosphate, the adsorbent layer comprises plasma activated carbon nanotubes, and the fibrous filter is a composite of polymethylmethacrylate, polyvinylidene fluoride, and polyvinylpyrrolidone polymer fibers, with carbon nanotubes that are dispersed within the polymer fibers and silver nanoparticles that are deposited on the polymer fibers. Various embodiments of the water treatment system and methods of fabricating the photocatalytic nanocomposite sheet, the adsorbent layer, and the fibrous filter are also provided.

A novel approach, based on hybrid nanostructure gas sensors, to correlate metrics related to specific medical conditions to a signature created by the sensor's response to the Volatile Organic Compounds (VOCs) contained in human breath.

The present invention discloses a novel method and novel compositions comprising well-dispersed particulate metal materials, including metal nanoparticles and/or metal single-atom materials, on various substrates, said method comprising the use of atomic layer deposition (ALD) and optimization of the metal precursor dose time and the number of ALD cycles. Illustrative of the metals are Fe, Ni, Co, Ru, Rh, Ir, Os, Pt, Pd, and the like; and illustrative of the various substrates are carbon nanotubes (CNTs) (including multi-walled carbon nanotubes (MWCNTs), SiO.sub.2, TiO.sub.2, alumina, CeO.sub.2, ZnO, ZrO.sub.2, activated carbon, CuO, Fe.sub.2O.sub.3, MgO, CaO, graphene, and the like. The density of the dispersed metals on the substrates is significantly higher than the metal density

Disclosed is a method for preparing adrenochrome by catalytic oxidation using nitrogen-doped carbon nanotubes. The method catalyzes dissolved oxygen in an aqueous solution by the nitrogen-doped carbon nanotubes to rapidly oxidize adrenaline, which is completely transformed into adrenochrome. It is a novel preparation process of adrenochrome, which is simple, and has mild reaction conditions, high product purity, an impurity content less than 10.sup.−8%, and low subsequent processing cost, thereby having a great application prospect. The nitrogen-doped carbon tubes after use can be regenerated and recovered, and its reutilization is still able to realize the complete transformation of adrenaline. The high utilization rate of catalytic material conforms to the concept of energy conservation, minimizing the costs.

A catalyst includes a mesoporous material and catalytic metal particles supported at least within the mesoporous material and containing platinum and a metal different from platinum. The mesoporous material has mesopores with a mode radius of 1 to 25 nm and a pore volume of 1.0 to 3.0 cm.sup.3/g before supporting of the catalytic metal particles, and has an average particle size of greater than or equal to 200 nm. A molar ratio of the metal different from platinum and contained in the catalytic metal particles relative to all metals contained in the catalytic metal particles is greater than or equal to 0.25, and among the catalytic metal particles, a volume ratio of catalytic metal particles having a particle size of greater than or equal to 20 nm is less than or equal to 10%.

A nanofibrous catalyst for in the electrolyzer and methods of making the catalyst. The catalysts are composed of highly porous transition metal carbonitrides, metal oxides or perovskites derived from the metal-organic frameworks and integrated into a 3D porous nano-network electrode architecture. The catalysts are low-cost, highly active toward OER, with excellent conductivity yet resistant to the oxidation under high potential operable under both acidic and alkaline environments.

A catalyst for synthesizing a carbon nanotube includes a support containing a metal, and an active metal impregnated on the support. The active metal includes cobalt and manganese. A surface molar ratio of the active metal relative to the metal of the support is 40% or less of a bulk molar ratio of the active metal relative to the metal of the support. A carbon nanotube having high purity and low resistance is obtained from the catalyst.

A visible light catalyst, its preparation method, a visible light catalyst activated persulfate system and its use. The visible light catalyst includes a carbon material, a transition metal compound and a coating material. The carbon material is conductive carbon material, and the transition metal compound is selected from one or more of transition metal oxides, transition metal sulfides, and acid or salt compounds containing a transition metal. The visible light catalyst has high visible light photocatalytic activity and performance of degrading organic pollutants and activating persulfate which can result in synergistically degrading degradation-resistant organic pollutants.